ANYONE who has seriously contemplated making money in real estate has probably encountered the arcane but potentially profitable practice of investing in tax liens at public sales -- the legal process through which municipalities obtain payment of delinquent property taxes.

Real estate experts say it is possible to make a secure investment with a high rate of return in property tax liens, even for unsophisticated investors. And savvier, more careful and more knowledgeable investors can even obtain title to real estate for a small fraction of its market value by buying property at a tax foreclosure sale, the experts say.